1. Field of the Invention
The present invention relates to a signal transmission circuit used between data line (or signal line) driver circuits of a display apparatus such as a liquid crystal display (LCD) apparatus.
2. Description of the Related Art
Recently, in an LCD apparatus, a plurality of driver circuits such as data line driver circuits formed by large scale integrated (LSI) circuits are mounted on a glass substrate of an LCD panel by a chips-on-glass (COG) process or a system-on-glass (SOG) process. In this case, the data line driver circuits are arranged by a cascade connection method using aluminum connections therebetween. Therefore, since the aluminum connections have large resistances, high speed signal transmission circuits are required.
A first prior art signal transmission circuit is constructed by a transmitter formed by a CMOS inverter, a receiver formed by a CMOS inverter, and a transmission line therebetween. This will be explained later in detail.
In the above-described first prior art signal transmission circuit, however, the higher the frequency of a transmitted signal, the larger the power consumption.
A second prior art signal transmission circuit uses a reduced swing differential signaling (RSDS) method in conformity with the interface standard of National Semiconductor Corp. This also will be explained later in detail.
In the above-described second prior art signal transmission circuit, however, the power consumption is still large. Also, since each signal transmission circuit requires two transmission lines, the signal transmission circuit is complex and large in scale.
A third prior art signal transmission circuit is constructed by precharging circuits for precharging the input and output, respectively, of a transmission line, in order to decrease the power consumption (see: JP-A-2001-156180). This also will be explained later in detail.
In the above-described third prior art signal transmission circuit, although the power consumption can be decreased, the precharging circuits are required, which would complicate and increase the circuit configuration in size.